This study investigated the role of lipids in the flavor evolution of ultra-high temperature sterilized (UHT) milk. Volatile compounds (VOCs) in UHT whole milk (UWM) and skim milk (USM), together with lipid composition in UWM, were monitored over 45 days at room temperature. The results showed that 35 VOCs were detected, with ketones over 70%. 2,3-butanedione, 2-heptanone[M], pentanal[M], and acetic acid ethyl ester[M] were the key VOCs influenced by lipid content. Among them, the peak areas of three were significantly higher in UWM compared to USM (P < 0.05). Lipidomics analysis identified 1633 lipids in UWM, with 19 glycerides, 27 glycerophospholipids, and 25 sphingolipids as differential lipids which served as main precursors for VOC formation. Correlation analysis further revealed phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol with 16-, 18-, and 20‑carbon fatty acids, and ceramides were important precursors of key VOCs. These findings provide a theoretical basis for improving UHT milk flavor and storage stability.

Epithelial-to-mesenchymal transition (EMT) that endows cancer cells with increased invasive and migratory capacity enables cancer dissemination and metastasis. This process is tightly associated with metabolic reprogramming acquired for rewiring cell status and signaling pathways for survival in dietary insufficiency conditions. However, it remains largely unclear how transcription factor (TF)-mediated transcriptional programs are modulated during the EMT process. Here we reveal that depletion of a key epithelial TF, ELF3, triggers a TGFβ signaling activation-like mesenchymal transcriptomic profile and metastatic features linked to the aminoacyl-tRNA biogenesis pathway. Moreover, the transcriptome alterations elicited by ELF3 depletion perfectly resemble an ATF4-dependent weak response to amino acid starvation. Intriguingly, we observe an exclusive enrichment of ELF3 and ATF4 in epithelial and TGFβ-induced or ELF3 depletion-elicited mesenchymal enhancers, respectively, with rare co-binding on altered enhancers. We also find that the upregulation of aminoacyl-tRNA synthetases and some mesenchymal genes upon amino acid deprivation is diminished in ATF4-depleted cells. In sum, the loss of ELF3 binding on epithelial enhancers and the gain of ATF4 binding on the enhancers of mesenchymal factors and amino acid-deprivation responsive genes facilitate the loss of epithelial cell features and the gain of TGFβ signaling-associated mesenchymal signatures, which further promote lung cancer cell metastasis.

The change in milk fat during storage greatly influences its flavor. This study investigates the effect of fatty acid composition on milk flavor by analyzing volatile compounds in pasteurized whole milk (PWM) and pasteurized skim milk (PSM) during storage at 4 degrees C. 33 types of volatile compounds were detected and the content of ketones was highest, followed by esters and aldehydes. Based on variable importance in projection and relative odor activity value, 2-hexenal dimer, acetic acid ethyl ester dimer, acetic acid ethyl ester, and butanal were identified as the key differential volatile compounds. These compounds were found in higher concentrations in PWM than in PSM, indicating a close relationship with the changes in the fatty acid composition of milk fat. Among 11 fatty acids detected in PWM, the content of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) decreased by 0.69 % and 49.1 %, respectively, while the content of monounsaturated fatty acids increased by 46.8 % during 15 days storage, which suggests that the oxidation of SFA and PUFA contributed more to the volatile compound formation. Correlation analysis between fatty acid composition and volatile compounds found that fatty acid C18:2 and C16:0 were strongly associated for 2-hexenal, acetic acid ethyl ester, and butanal. These fatty acids were mainly derived from neutral lipids or phospholipids. These findings provide a new perspective for the formation pathway of milk flavor.

In order to comprehensively analyze the antioxidant substances in sour jujube, total phenolic content (TPC) and total flavonoids contents (TFC) in different organs, including stem, leaf, flower, fruit pulp, and seed were analyzed for their contents and antioxidant activities. The results showed that leaves possessed significantly higher TPC and TFC (20.4 and 20.5 mg/g, respectively) than the other organs and have the highest antioxidant activity, which were also higher than the wild blueberry (A well-known for its high TPC). Subsequently, the variations in the antioxidant content and antioxidant activity of leaves were analyzed during leaf development. TPC in leaves sampled in may and august were significantly higher than that in other months, while the highest one was found in may. The n -hexane, ethyl acetate, n -butanol, and water fractions obtained from the main methanol extract of sour jujube leaves were evaluated for TPC and TFC and their antioxidant activity and it was found that ethyl acetate fraction displayed the highest TPC and TFC (184.5 and 193.3 mg/g, respectively), as well as the best antioxidant activity. In addition, using LC-MS and HPLC, ethyl acetate fraction was analyzed from qualitative and quantitative aspects; 31-one phenolic compounds, including catechin (33.0 mg/g), epigallocatechin (15.3 mg/g), quercetin 3- O -glucoside (11.4 mg/g), naringenin (6.7 mg/g), esculetin (4.8 mg/g), and chlorogenic acid (4.6 mg/g) were identified. Catechin, esculetin, epigallocatechin, chlorogenic acid, quercetin 3- O -glucoside, and naringenin exhibited high antioxidant activity. These results provide a theoretical basis for further study and utilization of flavonoid and polyphenols in sour jujube.

Adenylate cyclase is the key enzyme solely synthesizing cAMP which participates in cell metabolism regulations and functions as an intracellular second messenger. However, the biological functions of plant ACs have not been elucidated clearly for their poor conservative sequences and low detectable cAMP. We performed a systematic study of plant ACs by using Chinese jujube, whose fruit exhibits the highest cAMP content among plants. Three novel ACs were identified from Chinese jujube, and two types of methods including in vitro and in vivo were used to certificate ZjAC1-3 which can catalyze the conversion of ATP into cAMP. The biological functions of significant accelerations of seed germination, root growth, and flowering were found via overexpression of these AC genes in Arabidopsis, and these functions of ACs were further demonstrated by treating the AC-overexpressing transgenic lines and wild type Arabidopsis with bithionol and dibutyryl-cAMP. At last, transcriptome data revealed that the underlying mechanism of the biological functions of ACs might be regulation of the key genes involved in the circadian rhythm pathway and the hormone signal transduction pathway. This research established a foundation for further investigating plant AC genes and provided strong evidence for cAMP serving as a signaling molecule in plants.

The Ziziphus mauritiana Lam. and Z. jujuba Mill. are the two most economically important members of the genus Ziziphus. The fruit color of Z. mauritiana remains green throughout fruit development in the majority of commercial cultivars, whereas its close relative, Z. jujuba Mill. turns from green to red in all cultivars. However, the lack of transcriptomic and genomic information confines our understanding of the molecular mechanisms underlying fruit coloration in Z. mauritiana (Ber). In the present study, we performed the transcriptome-wide analysis of MYB transcription factors (TFs) genes in Z. mauritiana and Z. jujuba, and identified 56 ZmMYB and 60 ZjMYB TFs in Z. mauritiana and Z. jujuba, respectively. Through transcriptomic expression analysis, four similar MYB genes (ZmMYB/ZjMYB13, ZmMYB/ZjMYB44, ZmMYB/ZjMYB50, and ZmMYB/ZjMYB56) from Z. mauritiana and Z. jujuba were selected as candidate key genes regulating flavonoid biosynthesis. Among these genes, the ZjMYB44 gene was transiently highly expressed in fruit, and flavonoid content accumulation also increased, indicating that this gene can influence flavonoid content during the period of fruit coloration in Z. jujuba. The current study adds to our understanding of the classification of genes, motif structure, and predicted functions of the MYB TFs, as well as identifying MYBs that regulate flavonoid biosynthesis in Ziziphus (Z. mauritiana and Z. jujuba). Based on this information, we concluded that MYB44 is involved in the flavonoids biosynthesis pathway during the fruit coloring of Ziziphus. Our research results provide an important understanding of the molecular mechanism of flavonoid biosynthesis resulting in fruit coloration and laying a foundation for further genetic improvement of fruit color in Ziziphus.

Milk is a highly nutritional food rich in protein and fat that is prone to deterioration by oxidation and glycation reactions at storage and processing. In this study, glycation products and lipid oxidation products contents in skim milk, whole milk, and milk fat simulation groups were determined to evaluate the effect of milk fat components on glycation at 120 °C for 60 min. The increase rate of carbonyl compound, main advanced glycation end products (AGEs) levels, and glycation sites number of α-casein and β-casein are higher in whole milk than that in skim milk, indicating that milk fat promoted protein glycation significantly. In milk fat simulation groups, oleic acid and linoleic acid (LA) were added to milk fat in skim milk proportionally, promoting the formation of glycation products; however, palmitic acid had no such effect. LA exhibited strong promotion on AGEs formation. Lipid oxidation radicals, protein carbonyl amine condensation, and carbonyl compound formation were critical factors for milk glycation, according to OPLS-DA results. Therefore, radicals of fat oxidation are speculated to trigger the early glycation, and carbonyl compounds of fat oxidation act as important intermediates of glycation, fat type, form, and its degradation rate, thus play essential roles in milk glycation.

Research on advanced glycation end-products (AGEs) and their formation pathways in food processing has gradually increased because AGEs are associated with human health, especially with involvement of lipids. In this study, radicals and glycation products were detected via electron spin resonance (ESR) and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) respectively. The correlation of important intermediates was used to explain the effect of oleic acid (OA) on the glycation products and pathways. The results indicated OA participation decreased the content of stable radicals and glycosyl compounds in Maillard Reaction (MR). The oxidation of OA produced active radicals, and electron transfer caused lysine to transform radical form. These radicals participated in the formation of fructosyllysine (FL) with glucose (Glc) via the MR. The participation of OA is acted as inhibiting the way of Glc autoxidation and promoting the glycation pathway from FL to 3-deoxyglucosone (3-DG) to fluorescent-AGEs. Orthogonal projection to latent structures discriminant analysis results indicated that 3-DG, D-glucosone and methylglyoxal are key products in discriminating the glycation reaction.

The contents of glucose, N-epsilon-(carboxymethyl)lysine (CML), and two main intermediate products, glyoxal (GO) and fructoselysine (FL), were determined, and the corresponding mathematical models were established to investigate the formation and kinetics of CML in a glucose-lysine model heated at 80 degrees C for 50 h. The effects of oleic acid (OA), temperature, and energy on CML formation were considered in the kinetic models. The mathematical modeling results suggested that glucose consumption was incomplete at 50 h and 80 degrees C. Although OA contributed to the formation of GO, CML was primarily formed from FL via the Maillard reaction, not from GO. The Arrhenius model was used to deduce that FL is the main pathway in the glucose-lysine-OA system because 88.39 kJ/mol of activation energy via the GO pathway was significantly higher than the 73.97 kJ/mol of activation energy via the FL pathway, and because the rate constant k(4) was higher than k(3) at different temperatures. OA (50 mmol/L) acted as a catalyst as well as a reactant in CML formation. This is the first study in which CML formation has been determined by both multi-response modeling and kinetic models based on glycation and lipid oxidation.

Food heating process causes increased protein glycation and the formation of advanced glycation endproducts (AGEs) which related with diabetes and ageing. Aloe vera (A. vera) extract is a potent antioxidant with established effects attributed largely to a key ingredient anthraquinone. This study investigated the inhibitory ability of the three anthraquinones from A. vera on the formation of AGEs in a heated model system at 70°C. Anthraquinones, including aloe-emodin (AED), emodin (ED), and chrysophanol (CSN), were extracted from A. vera and analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry. Under optimal extraction conditions, the extraction yield of the anthraquinones was 4.377 mg/g. Anthraquinones showed good inhibition toward the formation of glycation products; the inhibition rates of AED, ED, and CSN on crosslinked AGEs were 46.48%, 66.38%, and 57.32% at 10 μM concentrations. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis images also proved that the anthraquinones could significantly inhibit crosslinked AGE formation in a time-dependent manner. ED showed higher inhibitory ability than AED and CSN on the formation of Nɛ-(carboxymethyl)lysine and crosslinked AGEs. The results indicate that the antiglycation properties of these anthraquinones are likely related to the phenolic hydroxyl groups in their structures, but this ability is not related to their antioxidant activity, which probably depends on the whole structure of the quinone. Generally, the anthraquinones in A. vera, especially ED, can effectively inhibit AGE formation and reduce protein crosslinking during food processing, even at low concentration. Practical applications The inhibitory effects of three anthraquinones extracted from Aloe vera on the formation of AGEs were investigated in a heated model system. The results indicate Aloe can be used as an effective inhibitor of glycation products in food processing, moreover, this research can be useful for finding suitable nature inhibitors of AGEs for food processing.

Camellia oleifera oil has the reputation of “oriental olive oil”; it is important to detect the adulterated camellia oleifera oil. In this paper, NIR spectra were used to detect camellia oleifera oil adulterated with sunflower oil. Camellia oleifera oil adulterated with varying mass fraction of sunflower oil were prepared, i. e., 11 samples in 0%～10% with the gradient of 1%, 6 samples in 15%～40% with the gradient of 5%, 6 samples in 50%～100% with the gradient of 10%, and all the samples were divided into four groups such as A(0%～5%), B(6%～10%), C(15%～40%) and D(50%～100%). A total of 207 absorbance spectra(1 000～2 500 nm) were acquired by sampling 9 times in each adulteration. Calibration set was consist of two-thirds of the spectra data in each group selected randomly, and the validation set was made up of the last spectral data. After removing the noise in both ends of the spectra, principal component analysis(PCA) was used to reduce the dimensionality, then the first four PCs were used to build the support vector machine (SVM) identification model, and the identification accuracies of 96.38% and 94.20% in calibration and validation set were obtained. Furthermore, five characteristic wavelengths (1 212, 1 705, 1 826, 1 905 and 2 148 nm) were selected based on the loading of the PCs, the peaks or troughs of the original spectra and the chemical functional groups they were corresponding to. A NIR simplified SVM identification model was built by them, and the identification accuracies were 94.20% and 92.75%. Overall, both NIR spectroscopy and NIR characteristic spectra can realize the identification of camellia oleifera oil adulterated with sunflower oil, and the characteristic wavelengths, selected in this study, provide a basis for the design of corresponding instrument.

Advanced glycation end products (AGEs) are glycosylated metabolic products generated in vivo and are associated with aging-related diseases. They are also formed during heat treatment in food processing. In this work, we investigated the contribution of linoleic acid (LA) to AGE formation using a protein/glucose model. An electronic tongue, denaturing polyacrylamide gel electrophoresis, electron spin resonance spectroscopy, circular dichroism, and ultra-performance liquid chromatography-tandem mass spectrometry were used to analyse reaction intermediates and reactive radical formation. The results show that LA is the key factor responsible for the change in flavour including the rapid triggering of glycation reactions. The amount of lipid-induced reactive radicals was significantly higher than in the non-fat system, radical generation in the non-fat system was gradually quenched after a robust radical-yielding reaction in the first 25 minutes. Subsequent unsaturated lipid oxidation, and AGE accumulation surpass Maillard reaction-only outcomes. Initial LA-induced changes in protein structure are followed by glycation and are enhanced by hydrophobic interactions and increased carbonyl levels resulting from lipid oxidation. These findings implicate lipids and lipid oxidation as the main factors responsible for AGE formation during the processing of fat-rich unsaturated fatty acid-containing foods.

研究一种不饱和脂肪酸——亚油酸对糖基化反应体系主要中间产物及终产物的作用,探讨在食品加工中不饱和亚油酸对晚期糖基化产物的影响。建立亚油酸、D-葡萄糖和L-赖氨酸反应的微乳体系,采用紫外-可见吸光光度法检测中间产物乙二醛、丙二醛和果糖胺的生成量;荧光法检测戊糖素和荧光性晚期糖基化终产物（advanced glycation end-products,AGEs）的生成量;高效液相色谱法检测终产物羧甲基赖氨酸[Nε-（carboxymethyl）lysine,CML]的生成量,分别比较各生成产物的变化,探讨亚油酸对反应途径的影响。结果显示:从中间产物上看,亚油酸能有效参与羰胺的糖基化反应,提高中间产物乙二醛含量,增加丙二醛含量,减少果糖胺的生成;从终产物来看,亚油酸的存在对戊糖素的生成量影响不明显,但能明显抑制羧甲基赖氨酸的形成并抑制荧光性AGEs的累积。在糖基化反应体系中亚油酸的存在一方面能够氧化葡萄糖,使参与羰胺反应的葡萄糖减少;另一方面因氧化促进了乙二醛等活性醛的生成,从而加速乙二醛与赖氨酸之间的反应,减少了参与羰胺反应的赖氨酸含量;亚油酸参与反应使中间产物丙二醛含量增加,进而增加了羧甲基赖氨酸同源的羧乙基赖氨酸（CEL）的生成量,减少了非荧光性产物羧甲基赖氨酸和荧光性AGEs生成量。

In this study, the effect of carrier oils on the physicochemical properties of orange oil beverage emulsions was investigated. The beverage emulsions were prepared by soybean soluble polysaccharides (SSPS) using a two-stage processing of homogenization. Results showed that the presence of carrier oils could improve the physical properties of beverage emulsions, including droplet size, size distribution and turbidity, compared with only orange oil in oil phase of the beverage emulsion. And the effect of long chain triglycerides on the physical stabilities of beverage emulsions was significant (p < 0.05) than that with medium chain triglycerides (MCT). The oxidation rate of orange oil in the emulsion was faster compared to that of the orange oil/carrier oils in emulsions. However, the rheological properties of beverage emulsions were hardly dependent on the carrier oils. In addition, all the emulsions exhibited near-Newtonian fluid behavior. These findings revealed that the physicochemical properties of the beverage emulsions could be effectively improved by the presence of carrier oils.

OBJECTIVE:To investigate the effects of ultraviolet A (UVA) and ultraviolet B (UVB) on serum 1,25-dihydroxy-vitamin D3 and bone metabolism of ovariectomized rats and to compare them on bone metabolism.METHODS:In the study, 40 six-month female Sprague-Dawley rats were randomly divided into sham-operated control group (sham), osteoporosis model group (OVX), UVA irradiation group (OVX+UVA) and UVB irradiation group (OVX+UVB). Except the sham-operated control group, the remaining rats were ovariectomized to establish the osteoporosis models. After the model establishment, the UVA and UVB groups were exposed to UV irradiation with wavelengths of 340 nm and 313 nm, respectively. After the 15-week UV irradiation treatment, bone material density and serum 1,25(OH)2D3, osteocalcin (bone gamma-carboxyglutamic acid protein, BGP), calcium (Ca) and phosphorus (P) contents were measured.RESULTS:Compared with the sham group, the body weights [(486.5±55.7) g, (488.3±32.1) g, (494.1±49.8) g, vs. (408.6±36.1) g, P<0.01] were significantly higher in the model group, UVA group and UVB group; proximal femur BMD [(0.318±0.025) g/cm(2), (0.316±0.031) g/cm(2), (0.322±0.036) g/cm(2), vs.(0.386±0.027) g/cm(2), P<0.01], central BMD [(0.321±0.038) g/cm(2), (0.319±0.051) g/cm(2), (0.320±0.053) g/cm(2), vs.(0.347±0.044) g/cm(2), P<0.05], distal femur BMD [(0.320±0.028) g/cm(2), (0.318±0.030) g/cm(2), (0.322±0.036) g/cm(2), vs.(0.361±0.046) g/cm(2), P<0.01] were significantly lower in the model group, UVA group and UVB group. After the 15-week treatment of UV radiation, compared with the sham group, proximal femur BMD [(0.162±0.125) g/cm(2) vs.(0.293±0.076) g/cm(2), P<0.01], central BMD [(0.205±0.102) g/cm(2) vs.(0.306±0.031) g/cm(2), P<0.01] , distal femur BMD [(0.153±0.119) g/cm(2) vs.(0.274±0.017) g/cm(2), P<0.01] were significantly decreased in the model group; serum 1,25(OH)2D3 [(19.80±1.67) ng/L vs. (28.35±4.32) ng/L, P<0.01], BGP [(11.00±0.01) ng/L vs.(16.64±0.01) ng/L,P<0.01] and Ca [(2.14±0.10) mmol/L vs.(2.68±0.16) mmol/L,P<0.01] were significantly lower in the model group. Compared with the model group, proximal femur BMD [(0.248±0.092) g/cm(2), (0.218±0.123) g/cm(2), vs.(0.162±0.125) g/cm(2), P<0.01], central BMD [(0.272±0.010) g/cm(2), (0.275±0.036) g/cm(2), vs.(0.205±0.102) g/cm(2), P<0.01] and distal femur BMD [(0.251±0.009) g/cm(2), (0.242±0.063) g/cm(2), vs.(0.153±0.119) g/cm(2), P<0.01] were significantly increased in the UVA group and UVB group; serum 1,25(OH)2D3 [(29.47±4.54) ng/L, (27.56±6.33) ng/L, vs.(19.80±1.67) ng/L, P<0.01], BGP[(15.70±0.01)ng/L, (15.62±0.02) ng/L, vs.(11.00±0.01) ng/L, P<0.01] and Ca [(2.48±0.22) mmol/L, (2.58±0.13) mmol/L, vs.( 2.14±0.10) mmol/L, P<0.01] were significantly higher in the UVA group and UVB group. There were no statistical differences among the UVA group, UVB group and sham group.CONCLUSION:Both UVA and UVB may improve serum 1,25(OH)2D3 content of ovariectomized rats, promote bone formation, increase bone material density, and relieve bone loss due to osteoporosis.